1. Field of the Invention
This invention relates to an improved anchoring arrangement for use in conjunction with building construction having an overlying concrete slab, concrete deck, or steel frame structure secured to the upper limits of a partition or masonry wall. More particularly, the invention relates to construction accessory devices, namely, high-strength partition top anchors set within a slip tube embedded in the uppermost portion of the wall and interconnected with the overlying structure. The invention is applicable to structures subjected to high lateral forces.
2. Description of the Prior Art
In the past, investigations relating to the effects of various forces, particularly high lateral loads or forces, upon structures located in areas subject to hurricanes, tornados, earthquakes and related destructive natural occurrences, demonstrated the advantages of having high-strength anchoring components interconnecting the vertical wall with the overlying slab or deck structure. The present invention improves on the prior art partition anchoring systems.
Anchoring systems for wall construction come in varied forms depending on the wall materials and structural use. Ronald P. Hohmann and Hohmann & Barnard, Inc., now a MiTek-Berkshire Hathaway company, have successfully commercialized numerous devices to secure wall structures to overlying structures, providing widespread improvements that include increases in interconnection strength, ease of manufacture and use, and thermal isolation. The present invention is an improvement in interconnection strength and lateral force reduction between the vertical wall and the overlying horizontal structure.
Earthquakes, strong storms, hurricanes, typhoons, tornadoes and the lateral forces that they create are devastating to building structures. In the United States, like many other countries, wind damage to building structures amounts to millions of dollars each year in losses. Many houses and other small buildings in the Caribbean hurricane zone can lose their ROOFS to category 3 and 4 storms under current construction methods. Structural weaknesses occur at the tie-down of the overlying structure to the walls. Current construction methods often fail to withstand hurricane uplift forces without separation of the overlying structure from the walls. A properly designed and anchored building can resist such damage through the use of the present partition top anchor. A properly constructed building structure must be designed to resist both vertical loads (loads acting in an up and down direction) and lateral loads (loads acting in a direction parallel to the ground).
The primary focus of this invention is to protect against high lateral load forces. The two major lateral load forces result from high winds, such as those from a hurricane, and seismic forces, such as those resulting from an earthquake. Wind and seismic forces can occur from any direction and the structure must be designed to withstand such forces. Each major building component and connection between each component must be constructed so each has the capacity to resist all the loads and transfer such loads between them and into the foundation. This transfer of loads is known as the load path.
Lateral loads are either transferred into the overlying structure, when wind pushes against the walls perpendicular to the wind, or they originate directly in the overlying structure during seismic activity. To withstand such lateral loads, the structure must be engineered to provide an acceptable level of structural integrity so that life-safety is assured and structural damage is minimized. Much of the structural damage caused by high lateral loads occurs at a weak link in the structure—the juncture of the horizontal overlying structure with the vertical support structures. The present invention is focused upon this juncture.
Static connections such as those presented in Argay, et al., U.S. Pat. No. 6,058,669 and Ramirez, U.S. Pat. No. 5,782,048, between the horizontal and vertical component of a structure often result in the separation of the components during prolonged periods of high lateral loads. As a result, dynamic partition top anchors, where the anchor is set in a slip tube embedded within the vertical wall are utilized for construction of structures that will be subjected to high lateral loads. The dynamic partition top anchor is interconnected along a slot or channel in the overlying structure and permitted to adjust in vertical and horizontal directions during times of high lateral load forces, allowing deflection of the overlying structure above the wall without transferring compressive loads.
Prior art partition top anchors are designed as a combination of a steel rod and attachment welded dovetail head. Such design locates the welded connection portion outside the connecting channel, thereby subjecting the weld between the rod and dovetail head to high levels of lateral load forces. The high level load forces at the weld point result in structural failure and separation of the rod and dovetail head removing the anchored connection. The present invention improves the prior art design by reengineering the dovetail head as an integral component of the rod structure, bonding the dovetail head within the rod, thereby providing a high-strength welded connection. Further, the welded interconnection is fully set within the channel, thereby redirecting the lateral forces to the high-strength steel rod and away from the welded connection. The present invention provides greater protection against anchor separation and structural strength than the prior art designs.
None of the above prior art anchors or anchoring systems provide a high-strength partition top anchor that can resist large scale lateral forces. This invention relates to an improved anchoring arrangement for use in conjunction with building construction having a wall secured at its upper limit to an overlying structure and meets the heretofore unmet need described above.